Darwin : Begin rework of zero-fill sections.

Much of the existing work in the Darwin BSS and common sections
was to accommodate the PowerPC section anchors.  We want to segregate
this, since it might become desirable to support section anchors for
arm64.

First revision (here) is to use the same section conventions as the Xcode
toochains for BSS and COMMON.

We also drop the constraint about putting small items into data/static data
that was a work-around for Java issues (irrelevant for several editions).

gcc/ChangeLog:

	* config/darwin.c (darwin_emit_local_bss): Amend section names to
	match system tools. (darwin_output_aligned_bss): Likewise.

gcc/testsuite/ChangeLog:

	* gcc.dg/darwin-sections.c: Adjust test for renamed BSS and common
	sections.  Cater for 64 and 128 bit long doubles.

1 files changed, 14 insertions, 28 deletions

diff --git a/gcc/config/darwin.c b/gcc/config/darwin.c
index b64aaa7..2311648 100644
--- a/gcc/config/darwin.c
+++ b/gcc/config/darwin.c
@@ -2384,11 +2384,7 @@ darwin_emit_local_bss (FILE *fp, tree decl, const char *name,
 			unsigned HOST_WIDE_INT size,
 			unsigned int l2align)
 {
-   /* FIXME: We have a fudge to make this work with Java even when the target does
-   not use sections anchors -- Java seems to need at least one small item in a
-   non-zerofill segment.   */
-   if ((DARWIN_SECTION_ANCHORS && flag_section_anchors && size < BYTES_ZFILL)
-       || (size && size <= 2))
+   if (DARWIN_SECTION_ANCHORS && flag_section_anchors && size < BYTES_ZFILL)
     {
       /* Put smaller objects in _static_data, where the section anchors system
 	 can get them.
@@ -2414,16 +2410,13 @@ darwin_emit_local_bss (FILE *fp, tree decl, const char *name,
     }
   else
     {
-      /* When we are on a non-section anchor target, we can get zero-sized
-	 items here.  However, all we need to do is to bump them to one byte
-	 and the section alignment will take care of the rest.  */
+      /* When we are on a non-section anchor target (or not using section
+	 anchors, we can get zero-sized items here.  However, all we need to
+	 do is to bump them to one byte and the section alignment will take
+	 care of the rest.  */
       char secnam[64];
-      unsigned int flags ;
-      snprintf (secnam, 64, "__DATA,__%sbss%u", ((size)?"":"zo_"),
-						(unsigned) l2align);
-      /* We can't anchor (yet, if ever) in zerofill sections, because we can't
-	 switch to them and emit a label.  */
-      flags = SECTION_BSS|SECTION_WRITE|SECTION_NO_ANCHOR;
+      snprintf (secnam, 64, "__DATA,__bss");
+      unsigned int flags = SECTION_BSS|SECTION_WRITE|SECTION_NO_ANCHOR;
       in_section = get_section (secnam, flags, NULL);
       fprintf (fp, "\t.zerofill %s,", secnam);
       assemble_name (fp, name);
@@ -2434,7 +2427,7 @@ darwin_emit_local_bss (FILE *fp, tree decl, const char *name,
 	fprintf (fp, "," HOST_WIDE_INT_PRINT_UNSIGNED",%u\n",
 		 size, (unsigned) l2align);
       else
-	fprintf (fp, "," HOST_WIDE_INT_PRINT_UNSIGNED"\n", size);
+	fprintf (fp, "," HOST_WIDE_INT_PRINT_UNSIGNED",0\n", size);
     }
 
   (*targetm.encode_section_info) (decl, DECL_RTL (decl), false);
@@ -2559,9 +2552,8 @@ fprintf (fp, "# albss: %s (%lld,%d) ro %d cst %d stat %d com %d"
       return;
     }
 
-  /* So we have a public symbol (small item fudge for Java, see above).  */
-  if ((DARWIN_SECTION_ANCHORS && flag_section_anchors && size < BYTES_ZFILL)
-       || (size && size <= 2))
+  /* So we have a public symbol.  */
+  if (DARWIN_SECTION_ANCHORS && flag_section_anchors && size < BYTES_ZFILL)
     {
       /* Put smaller objects in data, where the section anchors system can get
 	 them.  However, if they are zero-sized punt them to yet a different
@@ -2586,16 +2578,10 @@ fprintf (fp, "# albss: %s (%lld,%d) ro %d cst %d stat %d com %d"
     }
   else
     {
+      /* Section anchors not in use.  */
+      unsigned int flags = SECTION_BSS|SECTION_WRITE|SECTION_NO_ANCHOR;
       char secnam[64];
-      unsigned int flags ;
-      /* When we are on a non-section anchor target, we can get zero-sized
-	 items here.  However, all we need to do is to bump them to one byte
-	 and the section alignment will take care of the rest.  */
-      snprintf (secnam, 64, "__DATA,__%spu_bss%u", ((size)?"":"zo_"), l2align);
-
-      /* We can't anchor in zerofill sections, because we can't switch
-	 to them and emit a label.  */
-      flags = SECTION_BSS|SECTION_WRITE|SECTION_NO_ANCHOR;
+      snprintf (secnam, 64, "__DATA,__common");
       in_section = get_section (secnam, flags, NULL);
       fprintf (fp, "\t.zerofill %s,", secnam);
       assemble_name (fp, name);
@@ -2605,7 +2591,7 @@ fprintf (fp, "# albss: %s (%lld,%d) ro %d cst %d stat %d com %d"
       if (l2align)
 	fprintf (fp, "," HOST_WIDE_INT_PRINT_UNSIGNED",%u\n", size, l2align);
       else
-	fprintf (fp, "," HOST_WIDE_INT_PRINT_UNSIGNED"\n", size);
+	fprintf (fp, "," HOST_WIDE_INT_PRINT_UNSIGNED",0\n", size);
     }
   (* targetm.encode_section_info) (decl, DECL_RTL (decl), false);
 }